The present invention relates to a notifying vibration generator for use in portable communications devices, such as portable telephones and pagers, or in small-sized devices, such as wristwatches and toys, and also to portable communications devices wherein the generator is used.
Small-sized devices, such as portable communications devices, are equipped with means for notifying the user, for example, of incoming calls or specified hours. The notifying means most widely used is a bell, or like means, for producing a sound. However, in view of a nuisance to people in the surroundings, more widely used in recent years are small devices which have incorporated therein not only notifying means resorting to sound but also means for vibrating the device for notification so as to use both the notifying means or selectively use one of them in accordance with the situation.
The sound generators conventionally in wide use include a ringer 100 shown in FIGS. 9, (a) and (b). The ringer comprises a magnetic circuit portion composed of a permanent magnet 101 and a yoke 102 and fixedly housed in a case 104. A coil 103 is fixed to the yoke 102, and a diaphragm is disposed as opposed to the yoke 102. The diaphragm 105 is secured at its peripheral edge to the case 104, A lid 106 having an opening is fixed to the case 104.
When current is passed through the coil 103, the yoke 102 is electrically magnetized, forming a magnetic pole at its top end. The magnetic pole on the yoke 102 and the magnetic pole on the diaphragm 105 cause the diaphragm 105 to be attracted to the yoke 102 if the poles are different or to be repelled by the yoke 102 if the poles are the same. When the current is passed through the coil 103 intermittently, therefore, the diaphragm 105 performs this movement repeatedly, vibrating air to produce sound waves, which propagate to the outside through the opening of the lid 106. Notice can be given with sound by setting the diaphragm 105 at an audio-frequency (about 20 Hz to about 20 kHz).
The vibration generator most widely used heretofore is a cylindrical dc motor 200 provided with an eccentric weight 202 on its rotary shaft 201 as seen in FIG. 10. When the motor 200 is energized, the eccentric weight 202 rotates with the shaft 201, generating vibration, which is transmitted to a device to realize notification with the vibration.
With the device incorporating both the means for notifying with sound and means for notifying with vibration, it is conventionally necessary to arrange the two means, i.e., the sound generator and the vibration generator, as described above. FIG. 11 shows such a portable communications device of the prior art. The drawing shows a portable telephone body 300, antenna 301, speaker 302 for incoming speech, microphone 303 for outgoing speech, display 304 and push buttons 305. The telephone body 300 has the above-mentioned ringer 100 for giving notice of incoming calls with sound, and the cylindrical dc motor 200 for giving notice of incoming calls with vibration. The prior art thus requires two separate notifying means, i.e., means resorting to sound and means using vibration, and accordingly has the problem that it is difficult to compact the device. Thus, the device requires a greater interior space than when single notifying means only is used.
An object of the present invention is to provide a notifying vibration generator having both the function of generating sound and the function of generating vibration, and to provide a compacted portable communications device by using the vibration generator.
The present invention provides a notifying vibration generator which comprises a first vibrator having a permanent magnet and supported by a first spring body on a fixing member, a second vibrator having a coil so disposed as to intersect the magnetic flux of the permanent magnet and supported by a second spring body on the fixing member, and a power supply connected to the coil for passing current of predetermined frequency through the coil. One of a first vibration system provided by the first vibrator and the first spring body and a second vibration system provided by the second vibrator and the second spring body is used as a sound source for producing sound waves of audio-frequency for propagation to the outside, and the other vibration system serves as a vibration source for transmitting vibration to the fixing member and vibrating a device.
When the coil is energized by the power supply, an interaction of the current and magnetic field produces an electromagnetic force acting between the first vibrator having the permanent magnet and the second vibrator having the coil. Accordingly, when current of periodically varying values is passed through the coil, each of the first vibration system and the second vibration system is subjected periodically to the electromagnetic force to undergo forced vibration. By virtue of the forced vibration, the vibration system serving as the sound source produces sound waves of audio-frequency, propagating the waves to the outside, and the vibration system serving as the vibration source transmits the vibration to the fixing member to vibrate a device.
The invention provides as another feature thereof a portable communications device characterized in that the device comprises a vibration generator having a first vibrator having a first natural frequency, a second vibrator having a second natural frequency, and a magnetic circuit composed of a coil and a permanent magnet for driving the first and second vibrators; first and second signal generating means for producing signals with frequencies in match with the first and second natural frequencies respectively; switch means for selecting one of the signals to be produced by the first and second signal generating means and feeding the selected signal to the vibration generator; means for detecting incoming calls; and switch means for controlling the switch means according to selection by the user upon the detecting means detecting an incoming call.
Thus, when an incoming call is detected by the call detecting means, the user is notified of the incoming call with vibration or released sound as selected by the user in advance.